phil nw.

Definitely Ok Si! That trough gets so far south even our Iberian friends would feel the chill if that was to come about.

Talking about snow chances later next week could be interesting for more locations. UK model t120 That ne wind increases days 4/5 and extends further south. Early days but that should increase showery activity with it spreading further inland. Well worth watching shorter range models for updates on this.

We are indeed seeing some signs of the cold relaxing in a few days but will it only be for a short time? I have been looking through a bit of data to try and see where we are and where we might go. A view of some combined graphs from the different model runs and some of the ensembles show the spread of possibilities rising sharply towards next weekend. Just at the point where the northern blocking signal fades and we see the push from the Azores with a small ridge.Nothing dramatic but enough to send a bit of a warmer air into the south at least. Later eps/gefs guidance still favour +ve arctic ht anomalies and our temperatures still generally below normal. It looks like overall we remain generally on the colder side of the jet ,allowing for the odd push close to the south.It's a case of whether the blocking re-asserts whilst we remain in this unusual pattern. As ever the often used observation of much uncertainy beyond the next 5/6 days seems the right phrase.At least there is no strong signal for a return to our usual zonality.

The lower Strat still showing weak zonal winds even though at the top normal speeds abound. Just shows the disconnect that continues towards Christmas. The upper vortex continues to get pushed around from wave 1 warmings. All points to another couple of weeks of troposphere blocking and a southerly tracking jet.

What's impressive about all those Matt is the members are pretty tightly grouped somewhere close to around -5c .The other trend is the cold outlook has been extended by a couple of days compared to ens earlier in the week. All signs this pattern wants to keep giving with the bulk of the vortex still over the Asian side.Just when it looks like the blocking starts to fade along comes more runs that maintain it.

I would take the Ecm option at t144 all day to reenforce the cold. Not sure many would get snow on the UK model anyway Ali.

Just outside the reliable but i like the way the UKMO is going . Starting to see the low extended further east up the channel as it disrupts. which helps to draw the colder air from the NE. A way to prolong the cold.Nice trend.

All the ens.sets here look pretty solid out to day 9-for Warks showing mainly around -5c uppers .Day 10 is where the 2 main ens. head milder although not as dramatic as the 06zGFS operational. As already said there is so much uncertainty on the development of the pattern before then wrt to whether we see the blocking signal fade enough to allow the Atlantic jet to move north. Ensemble sets can easily switch and we have seen any breakdown put back by a day or two already compared to earlier data.Not yet a trend but something to monitor in later runs i would say.

Much of N.Europe would be bitterly cold next week in this set up. Notice the Scandinavian trough has been pouring deep cold south for some time. The GFS 06z would send even colder air this way on any easterly.

This is so true Yesterday's ECM showed much weaker heights and the lows were able to track further north. Much better this morning but we need to see more runs like this to see if the blocking remains strong enough to drive those lows up the channel. If this happens we can see how the cold reenforces from the ne and prolongs the pattern. Lovely Ukmo run too.

Just a reminder folks.Any met office discussions, incl.videos off you tube, please post them here for any discussions. We have moved or hidden some content already. It prevents this busy thread going off topic. Cheers all.

When a pattern is dragged north like this it's as much a sign of the relaxation of northern heights.The lows have an easier path putting it simply. The fading block has been featured for a few runs so that and the spread in the medium term ens.were a warning sign to me. It may be a temporary blip and we get a rebuild of heights later but a shame if we lose this cold so quickly.

signs weren't good as early as T120 when the low phased with the Newfoundland trough and by t144 a merger with the Greenland trough. pulling the whole pattern and our battleground further north.

This is so true. I was but a lad then but we kept the surface cold and snow cover in spite of some quite modest uppers at times. We were very lucky with the repeating pattern that Winter,try as it did mild never won until March. Anyway back to the present.We are heading to a crossroads around day 6/7 to see if our cold pool can prevail. Signs that the blocking signal is relaxing next week but if we can build a wedge of heights to our north then it may be enough. We can see though why some of recent ensemble graphs show a wider spread next week.

Yes I saw the 06z set after I posted. They do keep the cold going to the end and it will be good for other models to go that route. I will leave that up though just for comparison.

Yes looking at the Warks set. The spread increases beyond day 6.

Yup I highlighted this yesterday. A push from the south west around mid month has been trending for a number of runs. Something to bear in mind but plenty of uncertainty on how we finish up after this. Any mild could be pushed back and the battleground would create some fun and games. For some it could be snow all through, snow to rain or even snow to rain and back to snow. It's all down to retaining enough of a blocking signal to stop the jet being dragged north and breaking up the cold pool. Sometimes even a wedge of heights can be enough.

No change to a cold outlook from the 12's with the disorganised vortex and a cold Arctic trough heading into the UK. Looking at the gefs output It certainly looks like we continue to see a trend to a decent period of quite cold and wintry conditions .There could well be some move by the Atlantic week 2 but how effective that will be against our cold pool remains to be seen. The Warks 12z.Gefs 850's are pretty tightly grouped for a decent cold spell for around 10 days. which suggests any inroads of Atlantic milder air shows up around 14/15th December.This is when we may see one of the Atlantic lows attack from the south west.The question then is will be get any low to undercut with sufficient blocking further north helping the cause. GFS mean chart T240 It's all to play for after that with no clear signal with as many cold as milder members beyond mid-month. Beyond 4/5 days we see so much variation in the models- a sign of an unusual pattern quite different our normal zonal westerlies.The main thing is the overall NH pattern is cold for a while.

A very messy GFS but i try to view things from an overall perspective too.Looking at these 2 images at day 7 we can see the effect of a -ve AO All the cold air has spilled south into mid-latitudes because the trop.vortex has been split apart forcing the jet well south. There is very little forcing at our latitude in the Atlantic hence once we get the cold trough here ,provided the Arctic blocking holds, the only way it can be shifted is from an attack from further south.The reason we keep looking at the low pressure coming from the south west -where any possible sortie against our cold will come. An unusual pattern indeed and as much as we look for snow from this the pattern in itself is fascinating to me as we watch this evolve.

It's complicated isn't it?- trying to see where the main features go as we head into the unknown. Simply put we see the results of cold air being spilled into mid-latitudes by a shredded trop.vortex! As long as there is sufficient Arctic blocks or wedges of +ve heights to keep the main jet heading towards Iberia then we keep in the colder side of the pattern.

I have just been out for my daily walk and I could already feel the edge to what is still a modest easterly. I am just anticipating how cold it will be by Thursday as the Arctic air arrives right down to the south coast and then beyond. Snow chances in quite a number of locations by the weekend by the looks,starting in the north by Tuesday. On the wider view with the NH pattern the blocking will move around and the Atlantic will inevitably try to attack the underbelly of our cold trough. At least by then we will have a very cold surface for the fight. There are too many options to honestly punt on the outcome but a battleground snow event is looking more likely next week. At least after all the anticipation we know the cold and some snow is coming this week.

Understandably anticipation is building for this cold spell but please guys try to keep on topic.Too many one liners and unrelated chat do clutter up what is a good thread tonight. Remember others are reading to learn about the model outputs, Thanks everyone.

Well coldies can't really complain about this evenings runs,wow,they seem to be getting more severe with the Arctic air heading this way starting as early as Tuesday when it arrives in Scotland-only 3 days away. I can recall only recently we were talking about uppers only in the -4/-5c range ,well they have gone colder as we have got closer as the near time charts show. Here are the main 3 at T120 with the uppers There we have it-universal agreement by day 5 that we see -8c into the south.Not the first time i have seen this over the years where we have a cold blocking pattern modeled and the cold gets upgraded in near time as modeling is able to fine tune detail. I don't think we have any concerns now abut cold enough air not reaching the far south,it goes into N.France by Friday. This is shaping up to be quite a notable cold spell and looking at the ensembles it's odds on we see the cold holding well into next week and maybe beyond. There may be attacks from the south west from time to time no doubt but that is where some of the best snow events can occur as mild head butts against a cold block. We don't start Winter off like this very often and to realise we are already feeling the chill off the current easterly but the main course from the north is only around 3 days away. Plenty of drama and excitement to come i am sure.

The UKMO fax issued earlier alongside this afternoons raw 850s for midday Tuesday day 3 if you like. The arrival of the Arctic air into Scotland along with snow showers.A further step towards what promises to be an increasingly cold and wintry week.I think snow interest quite widely under that cold trough towards Thurs/Friday.

Well what a shocker that ECM was in the later stages. The fly in the ointment does appear to be the rapid development of a seemingly innocuous sub tropical low over the far side of the Atlantic- a few images to illustrate.The culprit is towards the bottom right of the first image then follow it up towards the UK. It rides the strong sub tropical jet streak and merges with low pressure to our south west,deepens and pushes into the UK sweeping away the cold air. Quite a dramatic turn of events and something we wouldn't see on the mean charts. Hopefully this gets downgraded based on the ens. It's worth bearing in mind some approach of mild towards the south has always been on the cards next weekend- at least for a short period. Hopefully this remains the worst possibility and we see the cold hang on.